Urinary bladder transplantation in humans - current status and future perspectives

Urinary bladder vascularized allograft transplantation in humans is currently extensively being investigated worldwide, owing to the theoretical potential of this approach as a therapeutic option for individuals with end-stage, non-oncological bladder conditions or congenital bladder pathologies. To date, a successful attempt at urinary bladder autotransplantation was carried out in a heart-beating brain-dead research human donor. The robot-assisted surgical technique was shown to be optimal for performing this procedure, achieving a good performance in terms of both bladder allograft collection as well as vascular, ureterovesical and vesicourethral anastomoses. The urinary bladder vascularized allograft would be an alternative to traditional urinary diversion methods that rely on the use of intestinal segments, potentially avoiding adverse effects associated with these approaches. However, different from ileal urinary diversion, bladder transplantation would require lifelong immune suppression. Clinical trials are in progress to assess the vascularized bladder allograft transplantation technique, as well as the safety of this procedure in oncological and non-oncological indications. In this Perspective, the authors present the state of the art of vascularized composite bladder allograft transplantation in humans, discussing different surgical approaches used in the attempts carried out so far, as well as currently available diversion methods. The role of tissue engineering in the field of urinary bladder regeneration is also discussed.